1. Field of the Invention
The present invention relates to the field of pipe bending apparatus in general, and in particular to an automatic hydraulic system to sequentially engage different portions of the pipe that is subjected to the bending process.
2. Description of Related Art
As can be seen by reference to the following U.S. Pat. Nos. 2,938,564; 3,934,450; 4,331,018; and 5,237,847, the prior art is replete with myriad and diverse pipe bending apparatus.
While all of the aforementioned prior art constructions are more than adequate for the basic purpose and function for which they have been specifically designed, they are uniformly deficient with respect to their failure to provide a simple, efficient, and practical automatic hydraulic system that sequentially engages different portions of an elongated length of pipe that is to be subjected to the bending process in a predetermined pressure balanced fashion to accomplish the bending function.
As most individuals who operate pipe bending machines are all too well aware, the uneven application of bending pressure on a length of pipe most often results in the collapse of the pipe walls thereby rendering that particular pipe section useless, which is a waste of materials and causes the pipe bending process to be unnecessarily expensive.
As a consequence of the foregoing situation, there has existed a longstanding need for a new and improved type of automatic hydraulic pin up system for pipe bending machines that is pressure balanced and sequential in operation to insure that an even application of pressure is maintained throughout the pipe bending process, and the provision of such a system is a stated objective of the present invention.